Improved card with new reservations.

src/backend/data.rs

@@ -17,6 +17,95 @@ pub enum ApiResponse<T> {
     Error(String)
 }
 
+#[derive(Serialize, Deserialize, Clone, Copy, Debug, Default)]
+pub struct Page {
+    page_size: i32,
+    page_num: i32
+}
+
+impl Page {
+    pub fn new(page_size: i32) -> Self {
+        Self {
+            page_size,
+            page_num: 1
+        }
+    }
+
+    pub fn with_page(self, page_num: i32) -> Self {
+        Self {
+            page_num,
+            ..self
+        }
+    }
+
+    pub fn limit(&self) -> i32 {
+        if self.page_size == 0 {
+            i32::MAX
+        } else {
+            self.page_size
+        }
+    }
+
+    pub fn offset(&self) -> i32 {
+        (self.page_num - 1) * self.page_size
+    }
+
+    pub fn page_num(&self) -> i32 {
+        self.page_num
+    }
+
+    pub fn first(&mut self) {
+        self.page_num = 1;
+    }
+
+    pub fn prev(&mut self) {
+        if self.page_num > 1 {
+            self.page_num = self.page_num - 1;
+        }
+    }
+
+    pub fn next(&mut self) {
+        self.page_num = self.page_num + 1;
+    }
+
+    pub fn go_to(&mut self, page: i32) {
+        self.page_num = page;
+    }
+}
+
+#[derive(Serialize, Deserialize, Clone, Debug)]
+pub struct PagedResponse<T> {
+    page: Page,
+    record_count: i64,
+    data: Vec<T>
+}
+
+impl<T: Clone> PagedResponse<T> {
+    pub fn new(data: Vec<T>, page: Page, record_count: i64) -> Self {
+        Self {
+            page,
+            record_count,
+            data
+        }
+    }
+
+    pub fn is_first(&self) -> bool {
+        self.page.page_num() == 1
+    }
+
+    pub fn is_last(&self) -> bool {
+        self.page.offset() as i64 + self.page.limit() as i64 >= self.record_count
+    }
+
+    pub fn total_pages(&self) -> i32 {
+        (self.record_count as f64 / self.page.limit() as f64).ceil() as i32
+    }
+
+    pub fn data(&self) -> Vec<T> {
+        self.data.clone()
+    }
+}
+
 #[derive(Clone, Serialize, Deserialize, Debug, PartialEq, Eq, Validate, Default)]
 #[cfg_attr(feature = "ssr", derive(sqlx::FromRow))]
 pub struct Company {